Abstract:
The route of transmission of hepatitis C virus is still
controversial. Parenteral exposure via blood or blood products
leads to infection in the majority of cases, and the majority of
intravenous drug users become infected by repetitive exposure to
contaminated injection equipment. The risk of infection from a
single needlestick injury is 5-15% and may depend on the size of
the innoculum. Other parenteral routes of transmission may include
traditional healing practices and the use of contaminated medical
equipment. Transmission is less common within a family but the
prevalence of hepatitis C viral antibodies is higher in family
members and sexual partners of carriers than in the general
population. There are some well-documented instances of acute
hepatitis C occurring after a defined sexual exposure. Vertical
transmission is rare unless the mother has high levels of
circulating HCV RNA as may occur in those also infected with HIV.
The detection of hepatitis C in saliva and the higher than expected
prevalence of infection in dentists may point to the possibility of
transmission by salivary contamination. There remain large numbers
of hepatitis C carriers in whom no route of infection can be
identified.